Mars Atmosphere Mission Pursues Propulsion

Engineers at Lockheed Martin are edging ahead of schedule to complete assembly of the Maven spacecraft, which is designed to investigate why most of the atmosphere of Mars has largely disappeared.

The Mars Atmosphere and Volatile Evolution (Maven) vehicle is being put together at Lockheed Martin’s Space Systems Waterton site near Denver. Due to be launched in November 2013, Maven will travel through the upper reaches of the Martian atmosphere, gathering data that should help scientists reconstruct a climatic history of the planet.

The program is designed to determine how much of the Martian atmosphere has been lost over time by measuring the current rate of escape to space. Once the rate has been established, a team of researchers led by the University of Colorado, and managed by NASA’s Goddard Space Flight Center, will extrapolate backward in time.

“Maven is about understanding what happened to the atmosphere; where did it go?” says Jim Crocker, Sensing and Exploration Systems vice president and general manager. “When Mars lost its magnetic field, it lost its ability to deflect solar winds and this stripped the atmosphere. This will let us understand what happened.”

The spacecraft’s primary structure follows that of other recent space exploration craft such as Juno and the Phoenix Lander, and is built out of composite panels comprised of aluminum honeycomb sandwiched between graphite composite. Although weighing around 3,680 lb. when fully fueled and packed with instruments, the basic structure of the spacecraft itself weighs only 275 lb.

Work to integrate the propulsion system is getting under way following the installation of a large hydrazine propellant tank into the core of Maven. The 6-ft.-2-in.-tall tank can hold 450 gal. of hydrazine propellant and was built by ATK Aerospace in California. This large fuel tank is required for the mission’s propelled maneuver into the atmosphere, which Lockheed selected over the more time-consuming aerobraking alternative.

Following the completion of assembly and testing, Maven will be transported to Kennedy Space Center in August 2013 for payload integration. Other contributors to the program include the University of California-Berkeley Space Sciences Laboratory, which is building instruments; NASA’s Jet Propulsion Laboratory, which will provide program management as well as navigation support; the Deep Space Network; and the Electra telecommunications relay hardware and operations.